Electrical signal amplifier circuits with photo-detectors, such as photodiodes, can be used for a number of applications such as in digital versatile disc (DVD) players, and in compact disc (CD) players, and for many other applications. Conventionally, a dummy detector may be employed in order to achieve AC balance of the amplifier (equal input capacitance on both sides). Substitution of the capacitance of the dummy detector by a lumped capacitor of equal value does not work. Dummy detectors, however, take up significant portions of the die. Accordingly, mechanisms for eliminating the dummy detector from the amplifier circuit are sought.